How Did the Guild Come to Discover the Use of Spice and Navigation?

This would essentially be an unprecedented state of affairs in the history of human politics. It's like a place is not real unless the guild permits you to go there. And and in in having this topile option, it allows people to to basically pass out of the world of human beings in the emperium - almost like they've entered into an after life or something. So how did the guild come to learn of the use of spice and navigation? Well, as we come to learn in the done series, thee steersmen, or gild navigators, consume just massive amounts of milange,. so much that they have been altered into a kind of aquatic mammal that breathes and